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2 years ago

8

Find the value of: a) 8 9 × −3 4

1 answer:

german2 years ago

4 0

Step-by-step explanation:

89 multiplied by negative 34 gives a negative answer, since positive multiplied by negative is negative hence,

(89) × (-34) = -3026

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Use the following trinomial to answer the questions. x^2-6x-27 When going through the process of determining the factors, the tw

Sauron [17]

Answer:

The factors are 3 and -9

Step-by-step explanation:

The given trinomial is $x^2-6x-27$ .

We need to find two factors. We know that,

3(9) = 27

So,

$x^2-6x-27$ can be written as :

$x^2+3x-9x-27$ as two factors add up to get -6 and multiply to get -27.

Hence, the factors are 3 and -9.

5 0

3 years ago

3. Let sin 21 = 0.358. What is the value of x for cos x=0.358?

r-ruslan [8.4K]

Answer:

$\cos(69)$

Step-by-step explanation:

We will use the co-function identity for sine, where:

$\sin(x)=\cos(90-x)$

Since sin(21)=0.358=cos(x). This means that:

$21=90-x$

Solve for x. Add x to both sides:

$x+21=90$

Subtract 21 from both sides:

$x=69\textdegree$

Hence:

$\sin(21)=\cos(69)\approx0.358$

6 0

3 years ago

An electronic system has each of two different types of components in joint operation. Let X and Y denote the lengths of life, i

AURORKA [14]

Answer:

a

The average cost is $E(C) = 66$

b

The standard deviation of cost is $\sigma = 9.798$

Step-by-step explanation:

From the question we are told that

$E(X) = 4$

$E(Y) = 2$

$E(X^2) = 24$

$E(Y^2) = 8$

The cost of replacing the two component is C = 50 + 2 X + 4 Y

The variance of X is mathematically represented as

V(X) = $E(X^2) - [E(X)]^2$

Substituting values

$V[X] = 24 - 4^2$

$V[X] =8$

The variance of Y is mathematically represented as

V(Y) = $E(Y^2) - [E(Y)]^2$

Substituting values

$V[Y] = 8 - 2^2$

$V[X] =4$

The average of replacing the two component is

$E(C) = 2 * E(X) + 4* E(Y)$

substituting value

$E(C) = 50 + 2 * (4) + 4* (2)$

$E(C) = 66$

The variance of replacing the two component is

$V(C) = V(50 + 2X +4Y)$ Note: The variance of constant is zero

and X and Y are independent

=> $V(C) = 2^2 * V(X) + 4^2 * V(Y)$

substituting values

=> $V(C) = 4 * 8 + 16 * 4$

=> $V(C) = 32 + 64$

=> $V(C) = 96$

The standard deviation is

$\sigma = \sqrt{V(C)}$

substituting values

$\sigma = \sqrt{96}$

$\sigma = 9.798$

6 0

3 years ago

In the diagram above, rectangles DEFG and WXYZ are similar. The ratio of the area of DEFG to WYXZ is 1:4. A student's work to fi

zalisa [80]

Was the 12 of GF given??
The area ratio should be 1:4, so if l×w = area (a) of DEFG, then L×W = Area (A) of WXYZ.
Since 4:1 is 4×1, A = 4×a or 4a
Since GF is length (l) and is 12, we can say that 12w = a
12×4 = 48 for length of ZY (L), and WX is also 48, and to find W would be: 48W = A
48W = 4a, since A=4a
Not sure what else you want by the limited information given!

8 0

3 years ago

Read 2 more answers

How many liters of water should be added to 18 liters of a 14% bleach solution so that the resulting solution contains only 10%

HACTEHA [7]

<h2>Answer:</h2>

18 liter = 14% Bleach

............ = 10% Bleach

......=

$\frac{18 \times 10}{14}$

$\frac{180}{14}$

$= 12.9\%$

4 0

3 years ago

Read 2 more answers